refactor(core): centralize claude paths and command parsing

src/shared/extended-context-utils.ts

@@ -0,0 +1,29 @@
+/**
+ * Shared extended context helpers used by CLI + UI.
+ */
+
+/** Extended context suffix recognized by Claude Code. */
+export const EXTENDED_CONTEXT_SUFFIX = '[1m]';
+
+/** Check if model is a native Gemini model (auto-enabled behavior). */
+export function isNativeGeminiModel(modelId: string): boolean {
+  return modelId.toLowerCase().startsWith('gemini-');
+}
+
+/** Check if model already has [1m] suffix. */
+export function hasExtendedContextSuffix(model: string): boolean {
+  return model.toLowerCase().endsWith(EXTENDED_CONTEXT_SUFFIX.toLowerCase());
+}
+
+/** Apply [1m] suffix to model if not already present. */
+export function applyExtendedContextSuffix(model: string): string {
+  if (!model) return model;
+  if (hasExtendedContextSuffix(model)) return model;
+  return `${model}${EXTENDED_CONTEXT_SUFFIX}`;
+}
+
+/** Strip [1m] suffix from model string. */
+export function stripExtendedContextSuffix(model: string): string {
+  if (!model) return model;
+  return hasExtendedContextSuffix(model) ? model.slice(0, -EXTENDED_CONTEXT_SUFFIX.length) : model;
+}